COMP Cams 4136 Gear Drive System Part - Manual (Page 2)

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COMP Cams®
3406 Democrat Rd.
Memphis, TN 38118
Phone: 901.795.2400
Part #COMP4-152
Revised 7/22/11
Toll Free: 1.800.999.0853
www.compcams.com
Clearance Test 1:
6. Camshaft thrust bearing cover clearance test – With camshaft at max. rearward travel, place
clearance putty* over front face of the camshaft thrust bearing assembly. Install timing cover
with gasket. Hand tighten cover bolts. Remove cover and check putty.
7. Grind camshaft thrust bearing face as to provide the required .005"-.010" endplay clearance.
8. Install dog bone idler assembly as in Figure 1.
Notes: Power idler (large gear) must be installed on left hand side as shown below (when
you are facing the engine). Crankshaft gear will force power idler (large gear) into tight
mesh with camshaft gear as crankshaft rotates clockwise. Reverse idler (small gear)
should have free vertical movement of .005"-.075" when drive idler gear is in solid mesh
with cam and crank gears. Gear damage will occur from excessive friction if reverse
idler (small gear) does not have sufficient running clearance.
Clearance Test 2:
9. Power idler (large gear) axle/engine block clearance test – Reinstall dog bone idler assembly
as follows:
Note: In operation, idler axles are always in contact with the front cover. All engine
clearance is between engine block and drive idler axles as shown in Fig. 2. Put idler
gears about halfway in, then install cover (with gasket) and push into place. Remove
cover and that is where idler assembly will run. The chamfered end of power idler axle
must NOT touch block; grind off if necessary for at least .005" end clearance. Clearance
putty* can be used to accurately check axle/block end clearance. DO NOT TRAP
AXLES between block and front cover.